Supporting constrained devices and networks in the decentralised Internet of Things

The ongoing growth of the Internet of Things (IoT) offers great opportunities to improve the way we understand and interact with the physical world. However, existing approaches face a number of challenges from providing scalable and reliable services to users to addressing the need for security and privacy. We believe decentralised architectures offer a valuable alternative to centralised approaches. However, increased performance and communication requirements render existing decentralised technologies unsuitable for use with the constrained edge- and end-devices popular in the IoT. In this paper we address these limitations. First by extending DSF-IoT with a novel mechanism for delegation to enable transparent interactions with and between IoT services on constrained and unconstrained end-devices without the trust and privacy boundaries of existing approaches. Second, delegation is demonstrated through the creation of what we believe to be the first real-world heterogeneous decentralised IoT network spanning WSAN connected microcontrollers, Arm-based single board computers, and unconstrained x64 devices. Third, we qualify DSF-IoT for use on constrained edge-devices through the development of a constrained gateway prototype and test-bench for measuring the performance of IoT brokers under varying operating conditions. This demonstrates that DSF-IoT offers equivalent (or improved) performance to popular CoAP and MQTT brokers on constrained edge-devices while providing historical data storage and access as well as end-to-end trust and privacy. Finally we perform a functional comparison of DSF-IoT against existing protocols and research to highlight the advantages of our approach and the suitability of DSF-IoTs and delegation for use with constrained edge- and end-devices to enable the creation of a truly heterogeneous future decentralised Internet of Things.